Annxiety about ex-partner moving abroad

I'm a guy, I found this link through your statement regarding another site; I felt this would be a good place to share my concerns.

I was in a relationship for several years, and we had a child in the summer of 2014. The relationship didn't last, and his mother currently has custody; I have regular agreed visits. However, there is some talk that my ex-partner might want to take our son abroad on a permenant basis, to Italy. She is British, and has no family connections there, her main reason for wanting to go there is simply personal choice.

I'd be devestated by this: our son is the most important person in my life, and I've build my life and career plans around joined care. I also feel that the effect of this potential move is damaging my mental state of mind.

Can I ask for advice here? Has anyone experienced this, and experienced other case of this maybe?

Finally, my ex-partner is not the "baddy," and we are on generally good terms. But I'm worried.